This invention relates to a bookbinding machine.
There is known a bookbinding machine wherein adhesive is applied to one edge surface or back of a book comprising a plurality of piled sheets of paper to be bound together and a cover sheet is applied to the back of the book to which adhesive has been applied. There is also known a bookbinding machine wherein an adhesive applicator and a cover applicator are successively arranged in the path along which a clamper which clamps a plurality of piled sheets of paper to be bound into a book is reciprocated so that as the clamper is moved, the adhesive applicator applies adhesive to the back of the book, onto which a cover sheet is then applied by the cover sheet applicator.
In these types of bookbinding machines, it is sometimes required that before application of adhesive to the back of a book, the back of the book is cut and roughened and adhesive is applied to the cut and roughened surface of the back. It is customary to provide a milling device in addition to the adhesive applicator and the cover applicator so that the milling device can selectively be used as occasion demands.
In a conventional bookbinding machine, a clamper which clamps a boundle of sheets of paper to be bound into a book is moved from a reference plate for defining the level at which one edge or back surface of the book is supported, and in the path along which the clamper is moved there are arranged a device for milling the back of the book, an adhesive applicator and a cover applicator. A book comprising a plurality of piled sheets of paper to be bound is placed on the reference plate so as to stand on its one edge or back and is clamped by the clamper, which carries the book along the above-mentioned path. First the milling device cuts the back of the book, to which the adhesive applicator applies adhesive so as to bind the book at the back, and then the cover applicator applies a cover sheet to the adhesive back of the book. Then the clamper is moved in the opposite direction as far as above the reference plate, where the clamper releases the book, which is taken out of the machine.
If the milling device is not used for bookbinding, the device is moved out of the path of the clamper by lowering the device a sufficient distance, so that milling operation is omitted. In this case, it is necessary not only to remove the milling device but also to adjust the height of the plane at which the adhesive applicator applies adhesive to the back of the book and the height of the plane at which the cover applicator applies a cover sheet to the back of the book.
The reasons why the removal and adjustment are required are as follows: When the milling device has cut the back of a book, the level of the cut surface of the back of the book becomes higher than that of the reference plate by the thickness the back of the book has been cut away. Therefore, the level of the plane at which the adhesive applicator applies adhesive must be adjusted so as to enable contact with the cut surface of the back of the book. Also the level of the plane at which the cover applicator applies a cover to the back of the book must be adjusted so as to enable application of a cover sheet to the adhesive cut surface of the back of the book.
On the contrary, when the milling device is not used, adhesive is applied to the back of a book as set by the reference plate and a cover sheet is then attached to the adhesive back of the book. In this case, obviously the level at which the back of the book is positioned is lower than the level at which the back of the book would be positioned if it were milled as in the previously mentioned case. Therefore, if the milling device is not used, the level of the plane at which the adhesive applicator applies adhesive to the back of a book and the level of the plane at which the cover applicator applies a cover sheet to the back of the book to which adhesive has been applied must be adjusted so as to conform to the level of the back of the book that was set on the reference plate.
In the prior art arrangement that the milling device is selectively put into and out of use, it is necessary not only to selectively set the milling device in the bookbinding machine and remove it from the machine but also to adjust the positions of the adhesive applicator and the cover applicator. This certainly is very inconvenient.
Accordingly, the primary object of the invention is to provide a bookbinding machine wherein it is not necessary to adjust the levels of the adhesive applicator and the cover applicator regardless of whether the milling device is used or not.
Another object of the invention is to provide a bookbinding machine wherein it is not necessary to set the milling device in the machine or remove it therefrom regardless of whether the device is used or not.
The invention will be described in detail with reference to the accompanying drawings.